Consumer knowledge, attitude, and purchasing behavior on

Ref. code: 25595802040773PVMRef. code: 25595802040773PVM

CONSUMER KNOWLEDGE, ATTITUDE, AND

PURCHASING BEHAVIOR ON DIETARY

SUPPLEMENTS FOR GENERAL HEALTH

PURPOSE AMONG YOUNG

ADULTS IN THAILAND

BY

MISS SUNHAPORN WONGSAWASDI

AN INDEPENDENT STUDY SUBMITTED IN PARTIAL

FULFILLMENT OF

THE REQUIREMENTS FOR THE DEGREE OF

MASTER OF SCIENCE PROGRAM IN MARKETING

(INTERNATIONAL PROGRAM)

FACULTY OF COMMERCE AND ACCOUNTANCY

THAMMASAT UNIVERSITY

ACADEMIC YEAR 2016

COPYRIGHT OF THAMMASAT UNIVERSITY


CONSUMER KNOWLEDGE, ATTITUDE, AND

PURCHASING BEHAVIOR ON DIETARY

SUPPLEMENTS FOR GENERAL HEALTH

PURPOSE AMONG YOUNG

ADULTS IN THAILAND

BY

MISS SUNHAPORN WONGSAWASDI

AN INDEPENDENT STUDY SUBMITTED IN PARTIAL

FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE

OF MASTER OF SCIENCE PROGRAM IN MARKETING

(INTERNATIONAL PROGRAM)

FACULTY OF COMMERCE AND ACCOUNTANCY

THAMMASAT UNIVERSITY

ACADEMIC YEAR 2016

COPYRIGHT OF THAMMASAT UNIVERSITY


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Independent Study Title CONSUMER KNOWLEDGE, ATTITUDE,

AND PURCHASING BEHAVIOR ON

DIETARY SUPPLEMENTS AMONG

YOUNG ADULTS IN THAILAND

Author Miss Sunhaporn Wongsawasdi

Degree Master of Science Program in Marketing

(International Program)

Major Field/Faculty/University Faculty of Commerce and Accountancy

Thammasat University

Independent Study Advisor Associate Professor James E. Nelson, Ph.D.

Academic Year 2016

ABSTRACT

The dietary supplements market is growing continuously as a result of hectic

city lifestyle. Despite the growing trend, Thai consumers still lack of basic

understanding on dietary supplements (Aungtipat et al., 2008). It is interesting to

understand the rationale behind these contrasting trends. The objectives of this

research are to understand consumer profile, to determine consumer level of

knowledge, attitude, and purchasing behavior on dietary supplements.

This study used both exploratory and descriptive research to gain overview of

the industry and insights from consumers. Exploratory research included secondary

researches, observation, and in-depth interviews. Descriptive research used

questionnaire in gathering the data. Qualitative analysis was analyzed by organizing

data, looking for patterns, and interpreting the findings. For quantitative analysis, the

data were analyzed using Statistical Package for the Social Sciences (SPSS).

The findings of this research found that the most common type of dietary

supplements was vitamin C and respondents took it for maintaining in good health.

They often purchased supplements from drug stores and they knew about dietary

supplements from family and friends. Their knowledge level was at a medium level

and they understood the basic level of dietary supplements knowledge such as the

purpose, targeted users, and the effectiveness. However, high level of knowledge did


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not translate into the high frequency of purchasing of the product, but attitude toward

dietary supplements did. The more positive attitude, the more frequent they would

likely to purchase dietary supplements, the higher average spending per month, and

the higher intention to repurchase dietary supplements again. The respondents would

look for the brand that has clear labeling, FDA approval, and reasonable price.

Keywords: Dietary supplements, Knowledge, Attitude towards dietary supplements,

Purchasing behavior


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ACKNOWLEDGEMENTS

I would like to express my deepest gratitude to my beloved advisor, Associate

Prof. Dr. James E. Nelson for the continuous support, dedication, guidance, insightful

recommendations, and encouragement until the completion of this Independent Study.

This study would not have been completed successfully without the support from my

advisor. It was an honor for me to have working with him.

I also would like to thank my friends from MIM29 and all respondents for

giving their time in completing the survey for my Independent Study.

Lastly, I would like to forward my sincere appreciation to my family members

for their understanding and continuous support.

Miss Sunhaporn Wongsawasdi


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TABLE OF CONTENTS

Page

ABSTRACT (1)

ACKNOWLEDGEMENTS (3)

LIST OF TABLES (7)

CHAPTER 1 INTRODUCTION 1

1.1 Introduction of the study 1

1.2 Operational definition of key terms 2

1.3 Research objectives 3

CHAPTER 2 REVIEW OF LITERATURE 4

CHAPTER 3 RESEARCH METHODOLOGY 9

3.1 Research design 9

3.2 Exploratory research methodology 9

3.3 Descriptive research methodology 10

3.4 Identification of key research variables 11

3.5 Target population 11

3.6 Data collection plan 11

3.7 Data analysis plan 12

3.7.1 Qualitative analysis 12

3.7.2 Quantitative analysis 13


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CHAPTER 4 RESULTS AND DISCUSSION 14

4.1 Exploratory research findings 14

4.1.1 Secondary research findings 14

4.1.2 Observation research findings 14

4.1.3 In-depth interview research findings 15

4.2 Descriptive research findings 16

4.2.1 Summary of respondent profile 16

4.2.2 Dietary supplements information 17

4.2.3 Dietary supplements usage pattern 18

4.2.4 Demographics and usage pattern 19

4.2.5 Knowledge on dietary supplements 20

4.2.5.1 Knowledge and supplements information 20

4.2.5.2 Knowledge and usage pattern 21

4.2.6 Attitude towards dietary supplements 22

4.2.6.1 Attitude and usage pattern 22

4.2.6.2 Attitude and level of spending 23

4.2.6.3 Factor analysis 24

4.2.7 Purchasing decision on dietary supplements 26

CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS 28

5.1 Conclusion 28

5.1.1 Respondent profile 28

5.1.2 Usage pattern on dietary supplements 28

5.1.3 Knowledge on dietary supplements 28

5.1.4 Attitude towards dietary supplements 29

5.1.5 Purchasing decision on dietary supplements 29

5.2 Recommendations 30

5.3 Limitations 30

REFERENCES 31


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APPENDICES 32

APPENDIX A: In-depth interview question guide 33

APPENDIX B: Questionnaire 34

APPENDIX C-a: Type of dietary supplements currently taken 40

by respondents (n=155)

APPENDIX C-b: Reasons for taking dietary supplements 40

APPENDIX C-c: Dietary supplements purchasing channel 41

APPENDIX C-d: Source of information about dietary supplements 41

APPENDIX D-a: Frequency of taking dietary supplements 41

APPENDIX D-b: Length of taking dietary supplements 42

APPENDIX D-c: Frequency of purchasing dietary supplements 42

APPENDIX D-d: Average spending per month on dietary supplements 42

APPENDIX D-e: Repurchasing intention on dietary supplements 42

APPENDIX E-a: Level of knowledge 43

APPENDIX E-b: Frequency of dietary supplements knowledge 43

APPENDIX E-c: Source of dietary supplements information 44

by knowledge groups

APPENDIX E-d: Purchasing channel of dietary supplements 44

by knowledge groups

APPENDIX E-e: Cross tabulation between knowledge groups 45

and usage pattern

APPENDIX E-f: Contingency coefficient and gamma values for 46

knowledge groups and usage pattern

APPENDIX F-a: Means of attitude towards dietary supplements 46

APPENDIX F-b: Cross tabulation between attitude and usage pattern 47

APPENDIX F-c: One-way ANOVA result for spending level and attitude 49

APPENDIX F-d: Correlation matrix of the attitude 50

APPENDIX F-e: Communalities of the attitude 51

APPENDIX F-f: Total variance explained of the attitude 51

BIOGRAPHY 52


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LIST OF TABLES

Tables Page

4.1 Summary of respondent profile (n=155) 17

4.2 Correlation between demographics and usage pattern 19

4.3 Summaries of attitude towards dietary supplements for 23

each spending group

4.4 Factor loading for attitude towards dietary supplements 25

4.5 Factor correlation matrix on attitude towards dietary supplements 26

4.6 Purchasing decision on dietary supplements 26


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CHAPTER 1

INTRODUCTION

1.1 Introduction of the study

In 2015, Thai consumers spent almost 50 billion baht on vitamins and dietary

supplements, and this number continued to grow at 11% (Euromonitor International,

2015). This increasing trend of dietary supplements was a reflection of Thai consumers’

hectic lifestyle and the increasing of health awareness. Nowadays, in this fast paced

environment, people cannot escape from the bustling city lifestyle. They spend most of

their time working and commuting, and often times neglecting to take care of their

health. Their daily diet and nutrition intake of fast food, high sodium dish, high sugar

content, and low carbohydrate meal cannot fulfill their body nutrition requirement.

Under these conditions, their health conditions have started to deteriorate. With that,

Thai consumers with health-conscious mindset have turned to dietary supplements as

an alternative choice to maintain in good health. According to research by Aungtipat et

al. (2008), the highest dietary supplement consumption for general health purpose were

in the young adults age 20-45 with 91% of the total sample size.

According to Euromonitor International (2015), the overall value of the dietary

supplements industry was growing but it was growing at a slower rate. This slower

growing rate was partly due to the price war competition among the competing brands

aiming to capture the price sensitive consumers. Although, the industry grew slower in

2015, companies still enjoyed the positive growth. Part of the growing value of the

market came from the fact that companies were continuously stimulating the demand

by introducing new products, vigorously advertising their brand, and offering their

products in convenient channels to consumers such as local pharmacy stores, malls,

retail shops, convenient stores, and even online channel.

The highly competitive environment and upward consumption trend of dietary

supplements still drove the market value to grow continuously. However, according to

Aungtipa et al. (2008), Thai consumers still lack of basic knowledge and understanding

on health, nutrition and dietary supplements. Often times, this problem caused many

consumers to be victims of false advertising and misunderstand the main purpose of


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dietary supplements. For companies, the lack of knowledge could translate into a lower

purchasing rate of the product.

Despite the lack of knowledge on dietary supplements among Thai consumers,

the dietary supplements consumption continued to grow. It is interesting to understand

the rationale behind these contrasting trends, their attitude towards dietary supplements,

and factors influencing the purchasing decision.

The Food Act of B.E. 2522 (1979) has categorized dietary supplements as a type

of food in addition to regular diet providing nutrients for normal people not patients. In

today’s market, dietary supplements come in various form including tablets, capsules,

powder, liquid, etc. The popular type of dietary supplements among Thai consumers

are multivitamin, fish oil, calcium and protein supplement (Euromonitor International,

2015).

From this study, companies and marketing professionals can tailor effective

marketing strategies for their dietary supplement products as well as have a better

understanding of current users of dietary supplements. This research studied in the area

of society and the research type is a contemporary topic in applied marketing that aims

to explore and understand consumers’ knowledge, attitudes and purchasing behavior

on dietary supplements for general health purpose among young adults in Thailand.

1.2 Operational Definition of Key Terms

Dietary Supplements: a food product intends to supplement the diet with nutritional

value, and it contains active dietary ingredients, either single or a mixture of substances,

aiming for normal people not patients.

Knowledge: facts and information acquired by a person through experience and

education

Attitude: an overall evaluation from one’s thinking or feelings about something that is

reflected in their behavior

Purchasing behavior: buying behavior of consumers which reflects from their

attitude, knowledge, preferences and intentions to buy when they are at a market place.


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1.3 Research objectives

This research studied in the area of society and the research type is a

contemporary topic in applied marketing. The first research objective is to understand

consumer profile of dietary supplements users by demographics including gender, age,

education, occupation, income, and health condition. The second objective is to

determine consumer level of knowledge on dietary supplements by determining the

minimum knowledge consumer should know before purchasing dietary supplements

and testing the level of knowledge about dietary supplements. The third objective is to

understand the attitude of consumer towards dietary supplements as well as their

satisfaction level on dietary supplements. Lastly, the fourth objective is to explore the

usage pattern on dietary supplements and determine factors influencing their purchase

decision on dietary supplements.


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CHAPTER 2

REVIEW OF LITERATURE

The relevant information about dietary supplements and consumer knowledge,

attitude and purchasing behavior from nine literature reviews were summarized. From

the literature reviews, dietary supplements are for supplementing to maintain in good

health and Thai consumers still lack of knowledge on dietary supplements. However,

with the health conscious trend is on its rise, dietary supplements products in Thailand

was growing. The sources of literature reviews includes both international and Thai

research studies, database, books, and government websites.

The survey of “Dietary Supplement Knowledge, Attitude and Use in a Rural

Population” in the United States by Owens (2014) stated that based on the survey

conducted with 526 adults, 72% of the respondents prefer dietary supplements over

conventional medication to maintain good health. Among the users, over 60% also used

the dietary supplements along with their medication and they had low concern over the

drug-supplement interaction side effects. For knowledge, Owens based his knowledge

testing over the regulations side of the dietary supplements in which the majority of

respondents recognized that FDA does not regulate dietary supplements the same way

as it does to drugs. With the usage of dietary supplement, vitamin is the most common

supplement followed by fish oil, cranberry, melatonin, etc. Most respondents “usually

or always trust the labeling of dietary supplements as much as they do to medications”

(Owens, 2014, p. 4), plus the ease of purchasing dietary supplements resulting in no

professional consultation prior to purchasing. However, the respondents tended to

discuss the use of dietary supplements with healthcare providers before receiving

medical treatment.

With the “Assessing Patients’ Attitudes towards Dietary Supplements as

Compared to Non-Prescribed Drugs” with 335 samples in Poland, the results showed

that more than half of the respondents did not consider dietary supplements as food in

which 40% of them considered dietary supplements as a type of drug (Wierzejska et

al., 2014). Majority of the respondents believed that taking dietary supplements help to

improve overall health, however, one third of respondents also expected dietary

supplement to treat diseases. They believed that the best place to purchase dietary


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supplements is pharmacy stores. Lastly, most respondents had stronger believe in non-

prescribed medicine than dietary supplements.

The study of “Factors Affecting the Purchasing Decisions of Dietary

Supplement Products in Bangkok” with 400 respondents (Sungthong, 2004) concluded

that majority of the respondents still lack of the general knowledge on dietary

supplements in terms of the main purpose, the target users, and the side effects. The

most influential social factor over the buying decision was through referral from friends

and family whereas the Thai FDA approval of the product was the main marketing mix

factor influencing the buying decision. The most common communication channel of

the dietary supplements product to respondents was television and brochures. These

respondents generally did not search for dietary supplements information on the internet

as the research was conducted in early 2000s when the internet was not widely used by

the residents.

The study on “Consumer Usage and Knowledge of Dietary Supplements in the

Northeastern of Thailand” showed that 69% of total respondents did not take any

supplements and only 14% of the total samples of 416 people took dietary supplements

and 42% of them took vitamins for general health purpose (Aungathipat et al., 2008).

Before purchasing a product, consumer looked at expiration date, manufacturing date,

packaging, place of manufacture and active ingredients respectively. As for the

knowledge, the research has concluded that consumers in the Northeastern of Thailand

generally lack of knowledge on dietary supplement and often times were victims of

false advertising. Around 60% of the total samples received a score of five or below

out of 25 on the knowledge test showing the low level of knowledge among the

Northeasterners. Therefore, in order to improve general knowledge, government should

provide the correct information to the public concerning appropriate nutrition intake,

product labeling, benefits, safety and risks of dietary supplements.

According to Euromonitor International (2015), Thailand’s vitamins and dietary

supplements industry in 2015 had a market value of 49.3 billion Baht with the growth

rate of 11% and this industry is expected to reach 70 billion Baht by 2020. Even though,

in 2015 this industry was growing, it was growing in a slower rate. The growth was

mainly due to the health conscious trend among Thai consumers and strong competition

in the market stimulating the demand by expanding distribution channels and starting


6

the price war aiming to capture the price-sensitive consumers. The industry can be

segmented by product’s positioning into ten categories namely; general health, bone,

heart health, beauty, digestive, eye, memory, joint, immune system and other. The

general health segment was the biggest category capturing 51% of the total dietary

supplements market in Thailand.

According to Consumer Behavior by Hoyer et al. (2013, p. 128-149), attitude is

“an overall evaluation that express how much we like or dislike an object, issue, person,

or action” (p. 128) in which it is based on cognitions and affection and translate our

overall evaluation through our behavior. With high motivation, ability and opportunity

to process information, consumers are more likely to form or change attitude and make

decisions. For marketers, in order to use cognitive to influence attitude effectively,

strong argument with credible source support should be considered. Moreover, with the

emotional messages, either positive or negative feelings can affect the change of

attitude. Lastly, attitude affects our behavior when consumers have high involvement,

high emotional attached and high knowledge.

According to The New Vitamin Bible by Mindell (2010, p. 4-17), many people

think of vitamin as a type of drug and this perception confuses people. Vitamin is an

organic substance that is crucial for our health. Our body cannot build vitamin by

ourselves, thus, we need vitamins from food and dietary supplements instead. In fact,

we do not need to take dietary supplements if we can eat sufficient amount of all five

food groups but most people cannot fulfill this fact. Thus, dietary supplements are

needed to maintain good health. All dietary supplements are considered as food

regardless of its forms because all of them are the extraction of plants or animal. Our

body can absorb vitamin well if taking with food. Each individual needs different

dietary supplements based on health condition, age, and lifestyle.

According to the “Dietary Supplements: What you need to know” by the United

States Office of Dietary Supplements (2011), there are four main areas of what people

need to know before purchasing dietary supplements. The first area that consumer

should look at is the label that list all the supplements facts with content and amount of

active ingredients per serving. Effectiveness is the second factor that consumer need to

understand. Dietary supplements are to support body for adequate amounts of nutrients

but it cannot replace variety of food that are important to you. The third element is


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safety and risks. Though dietary supplements are beneficial to consumers, it also have

adverse effect if use with other supplements or drug. Fourth, consumers should not take

dietary supplements to treat health condition that they diagnosed themselves, instead

they should consult with health care practitioners before taking dietary supplements.

The U.S. Food and Drug Administration raised an awareness of medications

and dietary supplements interaction in the article “Mixing Medications and Dietary

Supplements can endanger your health.” Often times, consumers take dietary

supplements with their medications but they are unaware that by combining

medications and dietary supplements could be dangerous to the body. For example,

taking aspirin and vitamin E together could increase the potential of internal bleeding.

Many consumers still believe that the “natural” dietary supplements such as herbs and

herbal extract are safe. In fact, natural products are not always safe if it was taken with

medications. In order to prevent the side effects from medications and dietary

supplements, consumers should always consult health practitioner before start taking

dietary supplements.

With nine literature reviews, the main ideas were summarized. The increasing

of health awareness and hectic lifestyle of consumers in Thailand have translated to the

growing market of dietary supplements to almost 50 billion baht in 2015 and expected

to grow to 70 billion baht by 2020 (Euromonitor International, 2015). Dietary

supplement is regarded as food containing organic substances that are crucial for health

(Mindell, 2010, p. 4-17). According to United States Office of Dietary Supplements

(2011), before purchasing dietary supplements, consumers should look at the labels,

understand its effectiveness, aware of safety and risk in taking dietary supplements, and

consult with health care practitioners before taking supplements. In addition, consumer

should also be aware that dietary supplements could interact with medication and could

have side effects. Thus before taking supplements, consumers should consult with

physician (U.S. Food and Drug Administration, 2014).

According to Owens (2014, p.4), the most common type of supplement was

vitamin and majority of the respondents prefer dietary supplements over conventional

medication to maintain in good health. In addition, patients in Poland also believed that

taking dietary supplements can help to improve overall health and they usually

purchased supplements at pharmacy stores (Wierzejska et al., 2014). In Thailand,


8

according to Sungthong (2004), family and friends were the most influential person,

and the main communication channel was television. Thai consumers usually took

vitamin for general health, however, they generally lack of knowledge on dietary

supplements (Aungathipat et al., 2008). According to Hoyer et al. (2013, p. 128-149),

attitude is how we express like or dislike on objects, issue, or topics, and attitude can

be changed with high motivation, affection and emotional messages.


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CHAPTER 3

RESEARCH METHODOLOGY

3.1 Research design

The research was conducted using both exploratory and descriptive research

methods. This study used both qualitative and quantitative research in gathering the

data. For qualitative, the data were gathered from secondary research, in-depth

interview and observation. Self-administered questionnaires was employed in

collecting data for quantitative research.

3.2 Exploratory research methodology

This exploratory research was conducted to obtain overview information of the

dietary supplements market in Thailand as well as to gain insights from current users

who purchased dietary supplement in the past three months. The data obtained from

exploratory research were used in developing descriptive research. Three types of

exploratory research were conducted including the secondary research, observations,

and in-depth interview.

The secondary research data were gathered to explore the industry overview of

the dietary supplements, consumers’ knowledge, attitude and purchasing behavior,

underlying problem related to this industry, and general information on dietary

supplements. The industry overview was gathered mainly from Euromonitor

International (2015) whereas consumers and underlying problem related to the industry

information were collected from various research studies by credible institutions.

Moreover, the sources for general information on dietary supplements were from

credible websites and books on dietary supplements. This overview of dietary

supplements gathered set a baseline measurement of knowledge consumers need to

know before purchasing supplements and were used to further develop self-

administered questionnaires.


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Observation was conducted in October 2016 to explore dietary supplement

products in terms of the type of supplements, brands, packaging, price and marketing

materials provided at local pharmacy stores, Boots and Watson. In addition, the

observation aimed to explore the purchasing process of consumers at a pharmacy store

in Silom and at a wellness clinic in Prakhanong. Through observation, the unbiased

purchasing process was witnessed. Although, there was a limit of not knowing

consumers’ thinking at the moment, useful information from observing were collected

including the purchasing patterns. The results from observation were used to develop

questionnaires.

In-depth interviews were conducted to understand the demographics, lifestyles,

knowledge, attitude, factor influencing their purchase decision, and usage on dietary

supplements of current users. The in-depth interview allowed interviewer to probe

deeply in order to understand the rationale behind consumers’ thoughts and decision.

The results from in-depth interview were expected to produce hypotheses on consumer

profile, knowledge, attitudes and purchasing behavior for further test and quantify in

the descriptive research (See Appendix A: In-depth interview question guide).

3.3 Descriptive research methodology

The descriptive research was carried out in the form of self-administered

questionnaires. The questionnaires was formed in order to gain statistical evidence to

generalize the findings regarding to consumer profile, knowledge, attitudes, and factor

affecting their purchasing behavior on dietary supplements. The consumer profile

included questions such as age, gender, occupation, income, etc. For the knowledge

based questions, it was in the form of multiple choice with single answer to test the

basic knowledge of respondents on dietary supplements. The attitude measuring

questions was in the form of Likert scale statements with scale of one to five where one

was strongly disagree and five was strongly agree. Lastly, questions regarding to

purchasing behavior were in the form of both multiple choice questions with multiple

answers and Likert scale statements. The questionnaire did not exceed 15 minutes to

complete. (See Appendix B: Questionnaire).


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3.4 Identification of key research variables

Key independent variables of this study were 1) Consumers’ characteristics

such as age, income, education, occupation, health condition, etc. 2) Basic knowledge

on dietary supplements they should know before purchasing the products. 3)

Consumers’ attitude towards dietary supplements whether their attitude is positive or

negative. 4) Factors influencing consumers’ purchasing decision including social

influences, marketing stimulations, etc.

The dependent variables of the research was usage pattern of dietary

supplements for general health purpose such as usage rate, purchase frequency, product

type, brand, purchasing channel, etc. These dependent variables showed the outcome

reflecting from the independent variables.

3.5 Target population

This research set target population for qualitative and quantitative research

methodology to ensure the unbiased data. The targeted respondents for in-depth

interview were both male and female age between 20-45 years old living in Bangkok

metropolitan area who purchased dietary supplements during the past three months.

The sample size of in-depth interview was seven. In contrast to the in-depth interview,

there was no target population set for the observation method as consumers who

purchased supplements came into the store by pure chance.

The quantitative target population had the same criteria as respondents from the

in-depth interview. The total quota for questionnaires was 150 respondents in which

the quota for each age range will also be set. Each age range, 20-29, 30-39, 40-45 was

at least 40 respondents to ensure equal distribution of respondents and unbiased results.

3.6 Data collection plan

Seven in-depth interviews were conducted in October and December in 2016.

Each in-depth interview took approximately 45 to 60 minutes and was sound recorded

for further analysis. The observation was conducted at Boots, Watson stores, a local


12

pharmacy store in Silom, and a clinic in Prakhanong area observing the dietary

supplement products and brands available in the market and consumers purchasing

process of dietary supplements in different settings. The observation in Boots and

Watson store took around 20-30 minutes whereas at the pharmacy store and the clinic

took around one to two hours.

The questionnaire was validated in pilot test before launching. The

questionnaire went through a pilot test and was launched during February 8 - February

27, 2017. The total number of respondents of the survey was 155 respondents age 20-

45 years old who purchased dietary supplements for general health purposes during the

past three months. The questionnaire was distributed through online channel, such as

social media and online communities including Pantip, Thai Love Health facebook

page, health and fitness online communities, and offline around Silom and Prakhanong

area. Convenience and snowball sampling were used for online and offline survey in

order to gather enough responds. In addition, at the end of the questionnaire, the

respondents were encouraged to share the questionnaire among their friends who

purchased dietary supplements during the past three month.

3.7 Data Analysis Plan

3.7.1 Qualitative analysis

The qualitative analysis focused on the insights gathered from in-depth

interview and observation. After each in-depth interview and observation, initial

conclusion was drawn as a memo to researcher for further analysis. The data from

qualitative research were analyzed by, first, organizing the insights into separate

sections according to the objectives and simplifying it into an understandable context.

Second, from the organized data, researcher looked for patterns in the data. Third, the

conclusions was interpreted from the patterns in which the findings were verified to

ensure the validity and realistic results. Lastly, the researcher connected all the findings

from both in-depth interviews and observation to form hypotheses for quantitative

analysis.


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3.7.2 Quantitative analysis

The quantitative data collected from self-administered questionnaires were

analyzed using Statistical Package for the Social Sciences (SPSS) to show frequency

distribution, relationships between variables through cross tabulations, and other

statistical analysis as appropriate. The findings from this study showed whether or not

there are significant relationships among the independent and dependent variables. For

example, using cross tabulations to show the relationship between the knowledge and

usage pattern, and using one-way ANOVA test to test the relationship between the

attitudes on dietary supplements and spending level. The results from SPSS analysis

were displayed in both tables and summarized in text.


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CHAPTER 4

RESULTS AND DISCUSSION

4.1 Exploratory research findings

4.1.1 Secondary research findings

In 2015, vitamins and dietary supplements industry in Thailand had a market

value of 49.3 billion Baht with the growth rate of 11% and this industry is expected to

reach 70 billion Baht by 2020. The general health segment was the biggest category

capturing 51% of the total dietary supplements market in Thailand (Euromonitor

International, 2015). Consumers believed that taking dietary supplements help to

improve overall health (Wierzejska et al., 2014). Dietary supplements are considered

as a type of food by Food Act of B.E. 2522 (1979) and it is aim for normal people not

patients. Our body can absorb vitamin well if taking with food. Each individual needs

different dietary supplements based on health condition, age, and lifestyle (Mindell,

2010, p. 4-17). According to U.S. Food and Drug Administration (2014), Consumers

of dietary supplements should be aware of the side effect from taking supplements with

other medication as it can have negatively effect on the body.

4.1.2 Observation research findings

The observations were conducted at a pharmacy store in Silom area and at a

wellness clinic in Prakhanong area aiming to explore the dietary supplement products

available including the type of supplements, brands, packaging, and price, and

observing the purchasing process of consumers. The products available at the pharmacy

store in Silom area were common dietary supplements including Thai herbal

supplements, multivitamin, vitamin C, fish oil, calcium etc. Whereas at a wellness

clinic, more specific supplements were available such as probiotics, enzymes,

melatonin, CoQ10, etc. The brands of supplements at both location had both domestic

brands such as Abhaiherb, Vistra, Mega we care, Hi-Balanz, etc and international

brands including Blackmores, Centrum, DHC, Caltrate, VitaHealth, etc. The price for

dietary supplements ranged from 200 Baht to 2,500 baht per bottle in which the price

of domestic brands was usually lower price than the international brands.


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The purchasing process of dietary supplements at the pharmacy store and at a

wellness clinic is different. At the pharmacy store, three patterns of purchasing process

could be recognized. First, consumers knew exactly what they wanted, and they tended

to purchase the product with no hesitation. They usually repurchased the products that

they had used and familiar with. Second, the first time buyers who would like to

purchase dietary supplements but undecided on the brand and product specifications.

This group needed more information of each brand for comparison such as product

specification, dosage, brand, and price. Lastly, the third pattern is the impromptu buyers

who bought dietary supplements based on the suggestion from the pharmacist. As for

the pattern at a clinic, only one pattern is recognized which is the purchase of

supplements based on doctor’s recommendations. The supplements purchased at

wellness clinics were usually more specific and higher in price. Although, the unbiased

purchasing processes were witnessed through observation, the limitation of unable to

know consumers’ thoughts were absent. The in-depth interviews were conducted to

further understand consumers in an in-depth level.

4.1.3 In-depth interview findings

The in-depth interviews were conducted during October to December 2016 with

the total of seven respondents. The in-depth interview allowed interviewer to probe

deeper to understand the rationale behind consumers’ thoughts and decision. Six out of

seven respondents were female and one was male with the age range between 20-45

years old, and all respondents had at least a bachelor degree with no underlying

diseases.

From the in-depth interview, generally respondents had good basic knowledge

of dietary supplements in terms of the main purpose and target consumers of dietary

supplements. They understand that dietary supplements were only to supplement our

body not to replace the food. They also acknowledged that only food they consumed

alone might not be sufficient to body’s nutrition requirement. Five out of seven

understand that dietary supplements helped in maintaining in good health for normal

people and not for treating a disease for patients, and regarded dietary supplements as

food whereas only two respondents though that dietary supplements were drugs.

As for the attitude, most of the respondents had a positive attitude towards

dietary supplements, however, only one viewed supplements toward the negative side.


16

For the respondents who have a positive attitude towards dietary supplements, they

would repurchase the dietary supplements even though they still could not see the

effectiveness upon themselves. They believed that dietary supplements would help

them in maintaining a good health. In contrary, the respondent with negative attitude

toward the dietary supplements believed that being healthy must come from the

changing of lifestyle and healthy diet. If she was to eat healthy food and exercise often,

she would not need dietary supplements. She was taking the supplements based on the

suggestion from a pharmacist.

When purchasing dietary supplements, all respondents looked for the credibility

of the brand, expiration date, and the price comparing with other brands. Two of the

respondents searched for testimonial and reviews on the internet to ensure the effective

result. Majority of the respondent would repurchase the dietary supplements with an

average spending of 1,500 Baht per month. Only one respondent ‘maybe’ repurchase

the dietary supplements again. They purchased dietary from drug stores, internet, and

multi-level marketing network.

Through this in-depth interview, respondents with good knowledge and positive

attitude were likely to repurchase supplements again. For the respondent with lower

knowledge on dietary supplement but with good attitude would still continue to

repurchase the dietary supplements. For the respondent with lower knowledge and

negative attitude, she ‘maybe’ repurchase the supplements again. From this result, the

knowledge, attitude and factors influencing the purchasing decision were to be

furthered analyzed through quantitative research.

4.2 Descriptive research findings

The data gathered from questionnaire were analyzed using SPSS (Statistical

Package of Social Sciences). The total respondents who purchased dietary supplements

during the past three months was 155 with the age between 20-45 years old.

4.2.1 Summary of respondent profile

The total collected respondents through questionnaire was 155 where by

74.20% were female and 25.80% were male with the age ranging from 20-45 years old.


17

Most respondents have at least a bachelor degree, 86.50%, and they were employee,

50.30%. Moreover, 38.70% of the respondents had an income ranging from 30,001-

50,000 Baht per month and most of the respondents did not have any underlying

diseases. The frequency and percentage were used to summarize the respondent profile

(See table 4.1).

Table 4.1 Summary of respondent profile (n=155)

Respondents' Demographic n % Gender Male 40 25.80%

Female 115 74.20%

Total 155 100.00%

Age 20-29 years old 54 34.80%

30-39 years old 51 32.90%

40-45 years old 50 32.30%

Total 155 100.00%

Education Below Bachelor 21 13.50%

Bachelor's degree 99 63.90%

Master's degree 33 21.30%

Ph.D 2 1.30%

Total 155 100.00%

Occupation Student 13 8.40%

Business owner 34 21.90%

Employee 78 50.30%

Government officials 8 5.30%

Freelance 18 11.60%

Others 4 2.60%

Total 155 100.10%

Income (Baht/Month) Below 15,000 22 14.20%

15,001-30,000 35 22.60%

30,001-50,000 60 38.70%

50,001-70,000 18 11.60%

70,001 & above 20 12.90%

Total 155 100.00%

Illness Yes 22 14.20%

No 133 85.80%

Total 155 100.00%

4.2.2 Dietary Supplements Information

From the survey, the information about dietary supplements were summarized

using frequency and percentage. The dietary supplements information includes types

of dietary supplements, reasons of taking dietary supplements, place of purchase and

communication channel where they know about dietary supplements.


18

The most common type of dietary supplements was vitamin C with 17.60%

followed by collagen at 10.3% and multivitamin at 9.50%. (See Appendix C-a: Type of

dietary supplements currently taken by respondents (n=155)). Moreover, the main

reasons for taking dietary supplements were for maintaining in good health at 33.20%

and prevent chronic diseases in the future at 21.40% (See Appendix C-b: Reasons for

taking dietary supplements). As for the place of purchase, the channel to purchase

dietary supplements were at drug stores at 29.00%, online at 15.80%, and Boots at

14.40%. The respondents seldom buy their dietary supplements at an event (See

Appendix C-c: Dietary supplements purchasing channel). In addition, the respondents

knew about dietary supplements information mostly through their family and friends,

website and doctor at 25.50%, 15.50% and 13.40% respectively. The respondents knew

about dietary supplements the least is through radio and newspapers (See Appendix C-

d: Source of information about dietary supplements).

4.2.3 Dietary supplements usage pattern

The usage pattern of dietary supplements were measured with the frequency of

taking supplements, the length of taking supplements, frequency of purchasing the

dietary supplements, the average spending on dietary supplements per month in Thai

baht, and repurchase intention. The data were summarized using frequency and

percentage. Majority of the respondents, 73.50% took dietary supplements four to seven

times per week, only 1.30% took dietary supplements less than once a week (See

Appendix D-a: Frequency of taking dietary supplements).

As for the length of taking dietary supplements, 62.58%, of the respondents had

been taking dietary supplements for six months or more. Only 2.58% or four

respondents had been taking dietary supplements for less than one month (See Appendix

D-b: Length of taking dietary supplements). Most of the respondents, 33.55%,

purchased dietary supplements every month whereas only 10.97% bought dietary

supplements once a year (See Appendix D-c: Frequency of purchasing dietary

supplements). Most respondents, 38.71%, spent around 501-1,000 baht per month on

average in purchasing dietary supplements. Only 10.97% spent 2,000 baht or more per

month (See Appendix D-d: Average spending per month on dietary supplements). With

regards to the repurchase intention, 67.70% would purchase dietary supplements again


19

whereas 32.3% ‘maybe’ repurchase again. None of the respondents chose ‘no’ to this

question (See Appendix D-e: Repurchasing intention on dietary supplements).

4.2.4 Demographics and usage pattern

The bivariate correlation was conducted to see the correlation between the

demographics of respondents and the usage pattern of dietary supplements. The result

from correlation analysis is shown in the table 4.2 below.

Table 4.2: Correlation between demographics and usage pattern

Usage

patter

n

1. Frequency of

taking

supplements

2. Length of

taking

supplements

3. Frequency of

buying

supplements

4. Average

spending/month 5. Repurchasing

Pearson

Correlation

p-

value

Pearson Correlation

p-value

Pearson

Correlation

p-value

Pearson

Correlation

p-value

Pearson

Correlation

p-value

Gender 0.05 0.52 0.00 0.96 -0.05 0.51 0.04 0.63 0.09 0.26

Age -0.03 0.68 0.26

0.00

* -0.25 0.76 0.06 0.47 -0.11 0.16

Education -0.06 0.44 0.26

0.00

* 0.16

0.05

* 0.13 0.10 0.02 0.82

Occupation -0.04 0.60 -0.12 0.14 -0.11 0.19 0.00 0.99 0.11 0.16

Income -0.02 0.79 0.31

0.00

* 0.21

0.01

* 0.23

0.00

* -0.07 0.37

Illness -0.03 0.74 -0.10 0.23 -0.30

0.00

* 0.00 0.99 -0.04 0.66

From table 4.2, the result shows that gender and occupation did not have effect

on the usage pattern on dietary supplements whereas age, education, income and illness

affected the usage pattern. Age of respondents had significant relationship with only

the length of taking dietary supplements at p=0.00 in which p < 0.05, however, age did

not have significant correlation with other variables of the usage pattern. Education also

had significant correlation with length of taking supplements and frequency of

purchasing dietary supplements with the p-value of 0.00 and 0.05 respectively where p

< 0.05. Apart from age and education, income also had significant relationship with

length of taking supplement at p=0.00, frequency of purchasing dietary supplements at

p=0.01, and average spending per month on dietary supplements at p=0.00 where p <

0.05. Lastly, illness also had significant correlation with frequency of purchasing

dietary supplements with p-value of 0.00 where p < 0.05 significant level. The relation

strength for all significant relationships mentioned earlier were rather weak as the

Pearson correlation ranged between -0.3 to 0.31 indicating the weak relationship.


20

4.2.5 Knowledge on dietary supplements

The knowledge questions intended to test the general knowledge on dietary

supplements in terms of its purpose, aimed target, side effects, and specific knowledge

about vitamin D and zinc. Also, a question was asked for respondents to rate the level

of knowledge they thought they had on dietary supplements with a scale of one to five.

The respondents thought that their knowledge on dietary supplements was at a medium

level with the mean of 3.27 and standard deviation of 0.85. Their actual knowledge on

dietary supplement was also at the medium level with the mean score of 6.05 out of 11

and standard deviation of 1.97. The knowledge score had been grouped into three

groups of low, medium and high in knowledge with the score between 0-4, 5-7 and 8-

11 respectively. 71.60% of the respondents fell into the medium level of knowledge

group while 20.00% was under the low level of knowledge and 8.40% was in the high

level of knowledge group (See Appendix E-a: Level of knowledge).

Respondents understood very well that dietary supplements took sometimes to

see its effectiveness at 14.30% and understood that dietary supplements aimed for

normal people not patients at 12.70%. In contrast, majority of the respondents

misunderstood that dietary supplements were safe as it was made from herbs and natural

substances at 20.20%. In fact, herbs and natural substances could interact with each

other and created side effects upon the users. In addition, most of the respondents at

14.80% ‘did not know’ that dietary supplements could interact with other drugs or

supplements if they were taken together (See Appendix E-b: Frequency of dietary

supplements knowledge).

4.2.5.1 Knowledge and supplements information

Cross tabulations were conducted for further understanding of each knowledge

level group and the source of information they received about dietary supplements, their

purchasing channel as well as their usage pattern. With the cross tabulation between the

level of knowledge groups and source of information, respondents from all knowledge

groups often gained information about dietary supplements from family and friends

with the highest frequency across three knowledge groups with the frequency of

25.71% for low, 26.43% for medium, and 22.89% for high knowledge group.

Moreover, the low knowledge group also learned about dietary supplements from the

websites with the frequency of 18.57% which was the same as the medium group. For


21

the high knowledge level group, apart from family and friends, they also gained

information from pharmacist, doctor and websites with the frequency of 14.46%. The

respondents from all three groups received dietary supplements information the least

from radio and newspaper. Expectedly, the high knowledge group knew about dietary

supplements from books more than the low knowledge group with 8.43% comparing to

1.43% for the low knowledge group (See Appendix E-c: Source of dietary supplements

information by knowledge groups).

By conducting the cross tabulation between knowledge groups with the

purchasing channels, drug store was the most common channel where all three

knowledge group purchased their dietary supplements with the highest frequency of

each group, 30.36% for low knowledge group. 29.70% for the medium group and

28.57% for the high knowledge group. The low knowledge group also purchased

dietary supplements from online channel, 17.86% which was the same as the high

knowledge group with 19.05%. For the medium knowledge group, they purchased their

dietary supplements from Boots store, 16.36%. The channel where they purchased

dietary supplements the least was at booth event (See Appendix E-d: Purchasing

channel of dietary supplements by knowledge group).

4.2.5.2 Knowledge and usage pattern

Three knowledge groups and usage patterns data were analyzed using cross

tabulation and chi-square test. By looking at the frequency generated from cross

tabulation, majority of the respondents from low, medium and high knowledge groups

took dietary supplements four to seven times per week with 87.10%, 68,50% and

74.30% respectively, and they had been taking the supplements for six months or more

with 71.00% for low, 59.60% for medium, and 62,90% for high knowledge group. The

low, 38.70%, and medium knowledge group, 33.70%, bought their supplements every

three months but the high knowledge group, 34.30%, purchased their supplements

every month. The respondents from all three groups usually spent around 501-1,000

Baht per month on dietary supplements, 41.90% for low, 34.80% for medium, and

45.70% for high knowledge group, and they would continue purchasing the

supplements. However, by looking at the Pearson’s Chi-Square value, none of the usage

pattern items had p-value less than 0.05 which indicated that the level of knowledge did

not affect the usage pattern on dietary supplements (See Appendix E-e: Cross tabulation


22

between knowledge groups and usage pattern). Moreover, the contingency coefficient

values ranged between 0.14 to 0.21 indicating a weak association between knowledge

groups and usage pattern, and gamma values also indicated a weak association between

the knowledge groups and usage pattern where gamma values ranged from -0.11 to 0.27

(See Appendix E-f: Contingency coefficient and gamma values for knowledge groups

and usage pattern). Thus, the hypothesis that knowledge level affected the frequency

of purchasing was rejected.

4.2.6 Attitude towards dietary supplements

The attitude towards dietary supplements were measured using Likert scale of

one to five in the aspects of the importance of dietary supplements, safety, the

effectiveness, labeling and advertising, value for money, and satisfaction on dietary

supplements. Overall, the attitude towards dietary supplements had a mean of 3.58

meaning that the respondents had a good attitudes toward dietary supplements. The

respondents believed that dietary supplements could help in improving overall health

with the highest means of 3.96 and generally, they were satisfied with the dietary

supplements they were taking with a mean of 3.93 as they thought that dietary

supplements was effective with the mean of 3.90. However, the respondents believed

that dietary supplements in the market were somewhat unreasonably priced with the

mean of 3.01 and they were less likely to continue purchasing dietary supplements if

they did not see the effectiveness of it with the mean of 2.99 (See Appendix F-a: Means

of attitude towards dietary supplements).

4.2.6.1 Attitude and Usage pattern

The means of attitude towards dietary supplements and usage pattern were used

in cross tabulation to analyze the relationship between these two variables. By looking

at the Pearson’s Chi-Square test, the attitude towards dietary supplements did not affect

either the frequency of taking supplements nor the length of taking supplements as the

p-value for both usage patterns were 0.51 and 0.59 respectively in which the p-values

were greater than 0.05 significant level. However, there were significant relationships

between the attitude and the frequency of purchasing, average spending, and repurchase

intention. The attitude significantly affected the frequency of purchasing dietary

supplements at p=0.001, the average spending on dietary supplements per month at


23

p=0.025, and repurchase intention at p=0.01 where p<0.05 (See Appendix F-b: Cross

tabulation between attitude and usage pattern).

4.2.6.2 Attitude and level of spending

In order to further understand the attitude towards dietary supplements among

the different average spending level groups, One-way ANOVA analysis was conducted.

The average spending per month on dietary supplements was grouped into three groups

of low, moderate and high spender groups. The low spender group spend up to 1,000

baht per month, moderate spender spent anywhere from 1,001 up to 2,000 baht per

month, and the high spender spent 2,001 baht or more per month. This analysis helped

in understanding the different attitude toward dietary supplements among the three

spending groups. The summary of attitude towards dietary supplements for each

spender group is shown in the table 4.3 below.

Table 4.3: Summary of attitude towards dietary supplements for spending

group*

Attitude Spending Level

Low (n=81)

Moderate

(n=39)

High

(n=35)

Mean SD Mean SD Mean SD F p-

value

1. Dietary supplements help

ccimproving an overall health 3.86 0.83 4.00 0.61 4.11 0.63 1.50 0.227

2. Dietary supplement is

important to you 3.63 0.80 3.59 0.79 3.71 0.75 0.24 0.784

3. Dietary supplements help

ccpreventing future diseases 3.32 1.00 3.82 1.02 3.94 0.80 6.61 0.002*

4. I take supplement as I do not

get sufficient nutrition from

food

3.69 0.86 3.67 0.77 4.31 0.80 7.93 0.001*

5. Consult with doctor before

ccpurchasing 3.69 1.21 4.08 0.84 4.26 0.85 4.13 0.018*

6. Dietary supplement is safe 3.43 0.91 3.51 0.97 3.60 0.85 0.43 0.650

7. I believe in labels of dietary

ccsupplements 3.49 0.92 3.51 0.88 3.49 0.89 0.01 0.991

8. I believe in advertising of

dietary supplements 3.15 0.99 3.13 1.00 3.00 1.00 0.28 0.756

9. Dietary supplements in the

ccmarket have reasonable price 2.99 1.01 3.21 0.86 3.06 1.03 0.65 0.523

10. Worth the money 3.41 0.74 3.41 1.04 3.66 0.76 1.22 0.299

11. Will repurchase as I

believed it is good 2.98 1.14 3.03 1.35 2.97 1.27 0.03 0.974

12. Supplement is effective 3.88 0.66 3.92 0.74 3.94 0.73 0.13 0.876


24

Table 4.3: Summary of attitude towards dietary supplements for spending

group*

13. Satisfied with supplements 3.89 0.63 3.90 0.82 4.06 0.64 0.79 0.455

14. Will recommend

supplements others 3.70 0.86

3.82 0.97 3.97 0.79

1.18 0.311

*Sample size is 155 for all tests

Table 4.3 shows the mean and standard deviation of attitude towards dietary

supplements of each spender group as well as showing the F score and the p-value.

From the table, most of the attitude towards dietary supplements were not different from

the level of spending as the p-value are greater than 0.05 significant level. However,

the attitude were significantly different from level of spending in term of the belief in

preventing future chronic diseases (F = 6.61, p < 0.002), the belief of not getting

sufficient nutrition from normal diet (F = 7.93, p < 0.001), and the belief of consulting

doctor before purchasing supplements (F = 4.13, p < 0.018). Thus, the stronger belief

in dietary supplements potential in preventing future chronic diseases, supplementing

nutrition to body, and consulting doctor before purchasing supplements affect the level

of spending on dietary supplements per month (See Appendix F-c: One-way ANOVA

for spending level and attitude).

4.2.6.3 Factor analysis

In addition, the Exploratory Factors Analysis was conducted to group the

attitude variables into several factors. Through the factor analysis, the correlation of all

the attributes were correlated (See Appendix F-d: Correlation matrix of the attitudes).

Moreover, the Kaiser-Meyer-Olkin value for this analysis was meritorious with value

of 0.87 meaning that the sampling for this test was adequate (Andale, 2016), and the

communalities of all attributes were greater than 0.50 confirming that one variable

shared some common variance with other variables (See Appendix F-e: Communalities

of the attitudes). Through the factor analysis, the total variance explained 67.04% of

the variance establishing four factors for the attitude toward dietary supplements (See

Appendix F-f: Total variance explained of the attitudes). With the reproduced matrix,

there were 9.00% nonredundant residuals with absolute values greater than 0.05. From

the factor analysis, four patterns were identified as shown in the table 4.4.


25

Table 4.4: Factor loading for attitude towards dietary supplements

Attitude towards dietary supplements Factor

I

Factor

II

Factor

III

Factor

IV

1. Dietary supplements help improving overall health .504 -.335

2. Dietary supplement is important to you .368

3. Dietary supplements help preventing future diseases .603

4. I take supplement as I do not get sufficient nutrition from

food .549

5. Consult with doctor before purchasing .585

6. Dietary supplement is safe .665

7. I believe in labels of dietary supplements .801

8. I believe in advertising of dietary supplements .546 -.319

9. Dietary supplements in the market have reasonable price -.764

10. Worth the money -.636

11. Will repurchase as I believed it is good

12. Supplement is effective .803

13. Satisfied with supplements .758

14. Will recommend supplements to others .721

From table 4.4: Factor loading for attitude toward dietary supplements, four

factors had been identified. Factor I consisted of three loadings including “Supplement

is effective” (0.80), “Satisfied with supplements” (0.76), and “Will recommend

supplements to others” (0.72). All the loadings under factor I were consistently high

with the value close to one meaning that factor I strongly affected all three variables,

and this first factor explained 40.58% of the variance. “Overall satisfaction” was the

label for factor I.

Factor II was labeled “Health and Nutrition” because the high loading under

this factor included “Dietary supplements help improving overall health (0.50),

“Dietary supplements is important to you” (0.37), “Dietary supplements help

preventing future diseases” (0.60), “I take supplement as I do not get sufficient nutrition

from food” (0.55), and “Consult with doctor before purchasing” (0.59). The small

loading on the importance of dietary supplements meant that this components was a

weak component in this factor. This factor explained 11.10% of the variance.

Factor III consisted of three loading items, “Dietary supplement is safe” (0.67),

“I believe in labels of dietary supplements” (0.80), and “I believe in advertising of

dietary supplements” (0.55). All the loadings were related to the information credibility

on dietary supplements, thus this factor was labeled “Information credibility beliefs”.

The third factor explained 9.42% of the variance. Lastly, the items related to value for


26

money were loaded into factor IV. There were two items within this factor which were

“Dietary supplements in the market have reasonable price” (-0.76) and “Worth the

money” (-0.64), and the fourth factor was labeled as “Value for money”. This last factor

explained 5.95% of the variance. Although the first three factors were positive values,

the factor IV, the “Value for money”, yield negative values.

Table 4.5: Factor correlation matrix on attitude towards dietary supplements

Factor Factor I Factor II

Factor

III

Factor

IV

Factor I 1.000 .343 .363 -.583

Factor II .343 1.000 .320 -.310

Factor III .363 .320 1.000 -.540

Factor IV -.583 -.310 -.540 1.000

Table 4.5 shows that factor I, II, and III were positively correlated whereas only

factor IV was negatively correlated with the rest of the factors. The negative loading of

factor IV or “Value for money” was explained with the questions asked in the survey

regarding to their attitude towards the market price on dietary supplement and the value

for money on their current dietary supplements. Although respondents believed that

dietary supplement was good for their health and were satisfied with the supplements,

they considered the price of the dietary supplements in the market was not reasonably

priced and it was not worth the money.

4.2.7 Purchasing decision on dietary supplements

The purchasing criteria for buying dietary supplements were asked using Likert

scale of one to five where one was strongly disagree and five was strongly agree. Table

4.6 shows the data distribution of purchasing criteria on dietary supplements.

Table 4.6: Purchasing decision on dietary supplements

Factors Strongly

disagree

Disagree Neutral Agree Strongly

agree

Mean SD

1. Recommendation

from family and friends 2 18 49 58 28 3.60 0.96

2. Recommendation

from doctor/pharmacist 8 15 29 64 39 3.71 1.10

3. Review from internet 17 32 50 41 15 3.03 1.14

4. Buy because of

seeing advertising 23 33 45 43 11 2.91 1.17

5. Imported brand 33 24 50 36 12 2.80 1.23

6. Domestic brand 24 32 62 32 5 2.76 1.05

7. Clear labeling 3 2 6 56 88 4.45 0.80


27

Table 4.6: Purchasing decision on dietary supplements

8. FDA approval 6 6 16 39 88 4.27 1.05

9. Good Manufacture

Practice 10 9 22 53 61 3.94 1.16

10. Promotion 12 12 59 56 16 3.34 1.03

11. Consider dosage

and amount 6 11 46 60 32 3.65 1.01

12. Reasonable price 1 6 19 91 38 4.03 0.76

13. Nice packaging 10 23 71 46 5 3.08 0.91

14. Convenient 6 13 56 58 22 3.50 0.97

15. Maintaining MLM 75 24 33 15 8 2.08 1.25

From table 4.6, the most important purchasing criteria on dietary supplements

for respondents was clear labeling with the mean of 4.45 followed by the FDA approval

product with the mean of 4.27. Respondents were less likely to purchase dietary

supplements to maintain multi-level marketing membership with the lowest mean, 2.08.

Moreover, the place of origin was not an important criteria on purchasing dietary

supplements since the question asked about purchasing only imported brands had a

mean of 2.80 and domestic brands had a mean of 2.76 which were relatively low

comparing to other variables. The exploratory factor analysis was carried out to analyze

the purchasing decision. However, the result was not meaningful as the KMO value

was only 0.68 meaning that the sampling was barely adequate for factor analysis.


28

CHAPTER 5

CONCLUSIONS AND RECOMMENDATIONS

The objective for this study is to understand consumer’s knowledge, attitude

and purchasing behavior on dietary supplements among young adults in Thailand. The

total number of respondents for this study was 155 respondents who were 20-45 years

old and purchased dietary supplements during the past three months. The data were

collected through observations, in-depth interviews, and questionnaires, and then

analyzed by SPSS program using frequency, cross tabulations, Pearson’s Chi-square

test, one-way ANOVA, and exploratory factor analysis tools in analyzing the data.

5.1 Conclusion

5.1.1 Respondent profile

This study founded that majority of the respondents from in-depth interview and

survey were female age between 20-29 years old. Most of the respondents had at least

a bachelor’s degree and were working as an employee. Their income ranged between

30,001-50,001 baht per month and did not have any underlying diseases.

5.1.2 Usage pattern on dietary supplements

The study founded that the most common type of dietary supplements was

vitamin C following by collagen and multivitamin. Majority of respondents took dietary

supplements mainly because of maintaining in good health and preventing future

chronic disease. They often purchased dietary supplements through drug stores and

online channel. Moreover, they knew about dietary supplements from family and

friends and website. The respondents took supplements four to seven days per week

and had been taking supplements for six months or more. They purchased dietary

supplements every month with an average spending of 501-1,000 baht per month and

they would repurchase dietary supplements again.

5.1.3 Knowledge on dietary supplements

The respondents had been summarized into three groups of low, medium, and

high based on their level of knowledge on dietary supplements. Medium knowledge

level was the largest group among the three and they understood very well that dietary


29

supplements took sometimes to see the effectiveness and it aimed for normal people.

However, more information regarding to the side effects of supplements should be

emphasized to consumer as respondents were not well aware of the dietary supplements

side effects and the harmfulness if supplements were to be taken together with other

drugs or supplements. All three groups of knowledge gained the information from their

family and friends as well as from website, and they often purchased supplements at

drug store. From the in-depth interview and survey, the level of knowledge did not

affect the usage pattern of dietary supplements. The lack of knowledge did not translate

into lower purchasing rate, thus the hypothesis that knowledge level affects the

purchasing of dietary supplements was rejected.

5.1.4 Attitude towards dietary supplements

Overall the respondents from both in-depth interview and survey had good

attitude towards dietary supplements. They believed that dietary supplements help in

improving overall health, and they were satisfied with their current supplements.

However, they believed that the dietary supplements in the market were unreasonably

priced and they would not purchase the supplements again if they could not see the

effectiveness upon themselves. The attitude towards dietary supplements affected the

usage patterns. The more positive attitude lead to more frequency of purchasing dietary

supplements, higher average spending per month, and higher intention to repurchase

dietary supplements again. The attitude could be divided into four different factors

namely, the overall satisfaction, health and nutrition, information credibility belief, and

value for money. Even though the respondents understand well about the supplements

and were satisfied with the supplements, they were less likely to purchase dietary

supplements if the price of supplement was unreasonable.

5.1.5 Purchasing decision on dietary supplements

The respondents were not strict themselves to only imported brands nor

domestic brands. However, when purchasing dietary supplements, the respondents

would look for the brand with clear labeling and had FDA approval as well as price at

a reasonable price. Pharmacist or doctor were the most influential to the respondents in

purchasing dietary supplements. The majority of the respondents were less likely to

purchase dietary supplements in order to maintain multi-level marketing membership.


30

5.2 Recommendations

Companies can focus customer with an age between 30-45 holding at least a

bachelor’s degree with no underlying illness as they are a group with highest frequency

of taking and purchasing dietary supplements. Moreover, positive attitude and

satisfaction on dietary supplements lead to higher frequency of purchasing, higher

average spending per month, and lastly more repurchase intention. It is wise for dietary

supplement companies and marketing professionals to build positive attitude towards

dietary supplements and increase satisfaction on the product. They can do this by

focusing on creating good quality, effective, and safe product. In term of safety,

companies should emphasize on educating consumers regarding to the side effects that

comes from the interactions between supplements and drugs, and create awareness of

harmful side effects among consumers before taking dietary supplements. Moreover,

companies should have clear labeling with expiration and manufactured date as well as

ingredients and benefits of the supplements. Dietary supplements companies should

distribute their product through drug stores and online as they are the most convenient

channels, and apart from communicating about the product to consumers, companies

should also focus on communicating the benefits and usage of the product through

pharmacists and doctors as they are the most influential personnel.

5.3 Limitations

There were limitations in this research including the small sample size of 155

respondents, sampling method using convenient sampling especially for the in-depth

interview and the time constraint in collecting and analyzing the data.


31

REFERENCES

Andale. (2016). Kaiser-Meyer-Olkin (KMO) Test for Sampling Adequacy. Retrieved

from http://www.statisticshowto.com/kaiser-meyer-olkin

Aungtipat, L., Limworranan, P., Panuwatsook, P., (2008). Consumer usage and

knowledge of dietary supplements in the Northeastern of Thailand. Journals of

Complementary and Alternative Medicine. Retrieved from

http://thaicamdb.info/article.php?article=89.

Euromonitor International. (2015). Vitamins and Dietary Supplements in Thailand.

Retrieved October 2, 2016, from Euromonitor Passport Database.

Food Act of B.E.2522 (1979), Royal Gazette. 122 (150). 376-379.

Hoyer, W. D., Maclnnis, D. J., & Pieters, R. (2013). Attitude based on high effort.

Consumer Behavior (pp. 128-149). Singapore: Cengage Learning Asia Pte.

Mindell, E. (2010). The world of vitamins. The new vitamin bible (pp. 4-17). (T.

Rujipattanikul M.D., Trans.). Bangkok: Aumarin Printing and Publishing.

Office of Dietary Supplements. (2011). Dietary supplements: what you need to know.

Retrieved from

https://ods.od.nih.gov/HealthInformation/DS_WhatYouNeedToKnow.aspx

Owens, C., Toone, T., & Steed-Ivie, M. (2014). A survey of dietary supplement

knowledge, attitudes, and use in a rural population. Journal of Nutrition &

Food Sciences, 4 (5) doi:10.4172/2155-9600.1000304

Sungthong, Tajjanok (2004). Factors affecting the purchasing decision of dietary

supplement products. Thammasat University. Retrieved from

http://beyond.library.tu.ac.th/cdm/singleitem/collection/thesis/id/10946/rec/1

U.S. Food and Drug Administration. (2014). Mixing medications and dietary

supplements can endanger your health. Retrieved from

https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm420349.htm

Wierzejska, R., Jarosz, M., Siuba, M., & Rambuszek, M. (2014). Assessing patients'

attitudes towards dietary supplements. Roczniki Państwowego Zakładu

Higieny, 65 (4), 317-323. Retrieved from

https://www.ncbi.nlm.nih.gov/pubmed/25526577


32

APPENDICES


33

APPENDIX A

IN-DEPTH INTERVIEW QUESTION GUIDE

Demographic:

1. Age:

2. Gender: M F

3. Education Level:

4. Occupation

5. Health concerns:

Knowledge:

1. What is dietary supplements?

2. Objective of dietary supplements? Treatment or just supplements?

3. To whom the supplements are mainly for? Regular people or patients in the

hospital?

4. Dietary supplements are classified as DRUG or FOOD?

Attitude:

1. Do you consider yourself to be a health-conscious individual?

2. Do you think that supplements are important to you or not?

3. Do you feel that the supplement is effective?

4. Are you satisfied with your supplements?

Usage pattern:

1. Have you taken supplements during the past three months? What did you

take?

2. Why did you take the supplements?

3. Where did you purchase supplements?

4. How much do you usually spend on supplements per month?

5. When you are purchasing supplements what do you consider before

purchasing dietary supplements?

6. Will you repurchase it again?


34

APPENDIX B

QUESTIONNAIRE

Section 1: Screening

1. Age (screening question)

Below 20 (Exit)

20 - 29

30 -39

40 - 45

Above 45 (Exit)

2. Are you currently residing in Bangkok?

Yes No

3. Are you currently taking any dietary supplements? (Screening Question)

Yes (Go to question 6)

Used to (Exit)

No (Exit)

Section 2: Purchasing of Dietary Supplements

4. What dietary supplements product are you currently/used to take? (Check all

that apply)

Thai herbs

Spilurina

Evening Primrose Oil

(EPO)

Fish oil

Multivitamins

Vitamin C

Vitamin B Complex

Zinc

Iron

Magnesium

Collagen

Calcium

Grape Seed extract

Alpha Lipoic Acid (ALA)

Glutathione

Folic Acid

Melatonin

CO Q10

Probiotics

Digestive enzyme

L-Carnitine

Protein powder

Others (Please specify)

5. Why do you take supplements? (Check all that apply)

Maintaining good health

Weight Loss

Enhance skin

Prevent chronic diseases

Ensure adequate nutrition

Others (Please specify)


35

6. Where do you purchase your dietary supplements? (check all that apply)

Boots

Watson

Local Pharmacy stores

Supplement shops (ie.

GNC)

Health shops

Online websites

MLM network

Booth event

Other (Please specify)

7. Where do you obtain information about dietary supplements? (check all that

apply)

Newspaper

Magazine

Pharmacist

TV

Radio

Meeting

Family and friends

Doctor

Books

Event booth

Websites

Social media

Other (please specify)

8. How often do you usually take dietary supplements?

4-7 days per week

1-3 days per week

Less than 1 day per week

No specific time

9. How long have you been taking dietary supplements?

Less than 1 month

1-3 months

3-6 months

6 months and above

10. How often do you purchase dietary supplements?

Every month

Every 3 months

Every 6 months

Once a year


11. How much do you spend on our dietary supplement on average per month?

Less than 500

501- 1,000 Baht

1,001-1,500 Baht

1,501- 2,000 Baht

More than 2,000 Baht

12. If you run out of supplements, will you continue to buy it again?

Yes Maybe No


36

Section 3: Knowledge

1. Based on your knowledge, how much do you know about dietary

supplements?

Very low 1 2 3 4 5 Very

high

2. Based on the FDA regulation, do you think that dietary supplements is

considered as drug or food?

Drug Food Do not

know

3. Can dietary supplements treat a disease?

Yes No Do not

know

4. Can dietary supplements help preventing chronic diseases?

Yes No Do not

know

5. Do dietary supplements take sometimes to see its effectiveness

Yes No Do not

know

6. Whom does the dietary supplements mainly aim for?

Normal people

Patient with diseases

Do not know

7. Dietary supplements are safe as they are made from herbal and natural

products

Yes No Do not

know

8. Dietary supplements do not have any side effect

Yes No Do not

know

Dietary supplements can interact with other supplements or medication

Yes No Do not

know


37

9. How long is the dietary supplements normal shelf life?

1 Year

2 Years

3 Years

4 Years

5 Years

10. Can vitamin D help in improving your immune system

Yes No Do not

know

11. Is Zinc a vital mineral for healthy hair

Yes No Do not

know

Section 4: Attitude & Satisfaction

How much do you agree with the following statements? (1=strongly disagree, 5=

strongly agree)

Statements Strong

ly

disagr

ee


Agree

1. Taking dietary supplements regularly helps

you maintaining good health 1 2 3 4 5

2. Dietary supplements are important to you 1 2 3 4 5

3. I take supplements to avoid health

problems later in life 1 2 3 4 5

4. I need dietary supplements as I do not

receive sufficient amount of food through

normal meal

1 2 3 4 5

5. Dietary supplements should be taken after

consultation with healthcare providers 1 2 3 4 5

6. Dietary supplements in the market are safe 1 2 3 4 5

7. I trust the labeling on dietary supplements 1 2 3 4 5

8. I trust dietary supplements advertising

claims 1 2 3 4 5

9. Dietary supplements in the market today

has reasonable price 1 2 3 4 5


38

10. Benefits received from taking dietary

supplements worth the money 1 2 3 4 5

11. After taking dietary supplements and still

do not see its effectiveness, I will

continue to purchase it because it must be

beneficial.

1 2 3 4 5

12. I believe that dietary supplements is

effective 1 2 3 4 5

13. I am satisfied with dietary supplements I

am currently taking. 1 2 3 4 5

14. You will recommend the supplements to

ddddothers 1 2 3 4 5

Section 5: Factors influencing purchase decision

How much do you agree with the following statements? (1=strongly disagree, 5=

strongly agree)

Statements Strongly

disagree


Agree

1. I purchase dietary supplements based on

family and friends’ recommendation 1 2 3 4 5

2. I purchase dietary supplement based on

doctor/pharmacist recommendation 1 2 3 4 5

3. I purchase dietary supplements based on

testimonials and review on internet 1 2 3 4 5

4. I purchase dietary supplements brands

that I see often on advertising 1 2 3 4 5

5. I buy only imported brands 1 2 3 4 5

6. I buy only domestic brands 1 2 3 4 5

7. I always look for clear label brand 1 2 3 4 5

8. I look for FDA approval sign 1 2 3 4 5

9. I look for GMP sign 1 2 3 4 5

10. I purchase dietary supplements because

of sales and promotion 1 2 3 4 5


39

Section 6: Demographic

1. Gender

Male Female

2. Education level

Ph. D.

Master degree

Bachelor's Degree

Below Bachelor's

Degree

3. Occupation

Student

Employee

Freelance

Business Owner

Government officials


4. Income per month (THB)

Below 15,000 THB

15,001 -30,000 THB

30,001 - 50,000 THB

50,001 - 70,000 THB

Above 70,001 THB

5. Do you have underlying

illness?

Yes (Please specify) No, I don’t have any

illness

11. Before purchasing, I look at the dosage 1 2 3 4 5

12. I look for reasonable price brand 1 2 3 4 5

13. I choose dietary supplement with nice

packaging 1 2 3 4 5

14. I purchase dietary supplements brands

that are available in many shops 1 2 3 4 5

15. I buy dietary supplements mainly

because of maintaining my

membership with MLM network

1 2 3 4 5


40

APPENDIX C-a TYPE OF DIETARY SUPPLEMENTS CURRENTLY TAKEN BY

RESPONDENTS (N=155)

Type of supplements n %

Thai Herb 29 5.86%

Spilurina 16 3.23%

EPO 9 1.82%

Fish Oil 40 8.08%

Multivitamin 47 9.49%

Vitamin C 87 17.58%

Vitamin B complex 21 4.24%

Zinc 16 3.23%

Iron 15 3.03%

Magnesium 7 1.41%

Collagen 51 10.30%

Calcium 33 6.67%

Grapeseed 19 3.84%

ALA 1 0.20%

Glutathione 14 2.83%

Folic acid 9 1.82%

Melatonin 6 1.21%

CoQ10 16 3.23%

Probiotics 7 1.41%

digestive enzymes 3 0.61%

L-Carnitine 16 3.23%

Whey Protein 26 5.25%

Others (Vitamin E, Chinese

herbs) 7 1.41%

Total 495 100.00%

APPENDIX C-b REASONS FOR TAKING DIETARY SUPPLEMENTS

Reasons of taking

supplements n %

Maintaining in good health 124 33.24%

Weight loss 25 6.70%

Skin 74 19.84%

Prevent future chronic

diseases 80 21.45%

Enough nutrition 64 17.16%

Others (Body building,

bone) 6 1.61%

Total 373 100.00%


41

APPENDIX C-c DIETARY SUPPLEMENTS PURCHASING CHANNEL

Dietary supplements purchasing

channel n %

Boots 41 14.40%

Watson 38 13.40%

Drug store 84 29.60%

Supplement store 15 5.30%

Health shop 17 6.00%

Online 45 15.80%

MLM 25 8.80%

Booth Event 5 1.80%

Others 14 4.90%

Total 284 100.00%

APPENDIX C-d SOURCE OF INFORMATION ABOUT DIETARY SUPPLEMENTS

Source of information n %

Newspaper 5 1.32%

Magazine 28 7.37%

Pharmacist 37 9.74%

TV 18 4.74%

Radio 4 1.05%

Meeting 9 2.37%

Family and friends 97 25.53%

Doctor 51 13.42%

Books 23 6.05%

Booth Event 15 3.95%

Website 59 15.53%

Social Media 34 8.95%

Total 380 100.00%

APPENDIX D-a FREQUENCY OF TAKING DIETARY SUPPLEMENTS

Frequency of taking supplements n %

4-7days/week 114 73.55%

1-3days/week 23 14.84%

Less than 1 day/week 2 1.29%

Take only when they can remember 16 10.32%

Total 155 100.00%


42

APPENDIX D-b LENGTH OF TAKING DIETARY SUPPLEMENTS

Length of taking dietary

supplements n %

Less than 1 month 4 2.58%

1-3months 30 19.35%

3-6months 24 15.48%

6 months & Over 97 62.58%

Total 155 100.00%

APPENDIX D-c FREQUENCY OF PURCHASING DIETARY SUPPLEMENTS

Frequency of buying supplements n %

Every month 52 33.55%

Every 3 month 49 31.61%

Every 6 month 26 16.77%

Once a year 17 10.97%

Others 11 7.10%

Total 155 100.00%

APPENDIX D-d AVERAGE SPENDING PER MONTH ON DIETARY SUPPLEMENTS

Average spending per month n %

Less than 500 Baht/month 21 13.55%

501-1,000 baht 60 38.71%

1,001-1,500 baht 39 25.16%

1,501-2,000 baht 18 11.61%

2,000 baht &above 17 10.97%

Total 155 100.00%

APPENDIX D-e REPURCHASING INTENTION ON DIETARY SUPPLEMENTS (N=155)

Repurchasing of dietary supplements n %

Buy 105 67.70%

Maybe 50 32.30%

155 100.00%


43

APPENDIX E-a LEVEL OF KNOWLEDGE

Level of knowledge n %

Low (0-4) 31 20.00%

Medium (5-8) 111 71.60%

High (9-11) 13 8.40%

155 100.00%

APPENDIX E-b

FREQUENCY OF DIETARY SUPPLEMENTS KNOWLEDGE

Frequency of dietary supplements

knowledge

Correct

Wrong

Do not Know

n %

n %

n %

1. Dietary supplements is considered as

food not drug 79 8.40% 42 9.30% 34 10.90%

2. Supplements cannot treat a disease 116 12.40% 27 6.00% 12 3.90%

3. Supplements can prevent chronic

disease 72 7.70% 63 14.00% 20 6.40%

4. Supplements takes sometimes to take

effects 134 14.30% 12 2.70% 9 2.90%

5. Supplements aim for normal people

not patients 119 12.70% 18 4.00% 18 5.80%

6. Dietary supplements are not 100%

safe even though it is made from herbs

and natural substance

23 2.50% 91 20.20% 41 13.20%

7. Dietary supplements have side

effects 71 7.60% 60 13.30% 24 7.70%

8. Supplements can interact with drug

or other supplements 68 7.30% 41 9.10% 46 14.80%

9. Normal shelf life of supplements is 2

years 81 8.60% 36 8.00% 32 10.30%

10. Vitamin D can help improving

immune system 71 7.60% 50 11.10% 34 10.90%

11. Zinc is important for healthy hair 103 11.00% 11 2.40% 41 13.20%

937 100%

451 100%

311 100%


44

APPENDIX E-c SOURCE OF DIETARY SUPPLEMENTS INFORMATION BY

KNOWLEDGE GROUPS

Source of

information

Knowledge Level

Low Medium High

Newspaper 0 0.00% 4 1.76% 1 1.20%

Magazine 5 7.14% 20 8.81% 3 3.61%

Pharmacist 6 8.57% 19 8.37% 12 14.46%

TV 3 4.29% 10 4.41% 5 6.02%

Radio 0 0.00% 4 1.76% 0 0.00%

Meeting 2 2.86% 5 2.20% 2 2.41%

Family and friends 18 25.71% 60 26.43% 19 22.89%

Doctor 11 15.71% 28 12.33% 12 14.46%

Books 1 1.43% 15 6.61% 7 8.43%

Booth Event 5 7.14% 10 4.41% 0 0.00%

Website 13 18.57% 34 14.98% 12 14.46%

Social Media 6 8.57% 18 7.93% 10 12.05% 70 100.00% 227 100.00% 83 100.00%

APPENDIX E-d PURCHASING CHANNEL OF DIETARY SUPPLEMENTS BY

KNOWLEDGE GROUP

Place of

purchasing

dietary

supplements

Knowledge Level

Low Medium High

Boots 7 12.50% 27 16.36% 7 11.11%

Watson 9 16.07% 23 13.94% 6 9.52%

Drug store 17 30.36% 49 29.70% 18 28.57%

Supplement store 2 3.57% 7 4.24% 6 9.52%

Health shop 3 5.36% 11 6.67% 3 4.76%

Online 10 17.86% 23 13.94% 12 19.05%

MLM 3 5.36% 14 8.48% 8 12.70%

Booth Event 0 0.00% 3 1.82% 2 3.17%

Others 5 8.93% 8 4.85% 1 1.59%

56 100.00% 165 100.00% 63 100.00%


45

APPENDIX E-e

CROSS TABULATION BETWEEN KNOWLEDGE GROUPS AND USAGE

PATTERN

1. Frequency of taking

supplements

Knowledge Level

Low Medium High X2 df p-value

4-7days/week 27 61 26 7.054 6 0.316

87.10% 68.50% 74.30% 1-3days/week 1 18 4

3.20% 20.20% 11.40% Less than 1 day/week 0 1 1

0% 1.10% 2.90% Take whenever 3 9 4

9.70% 10.10% 11.40%

2. Length of taking

supplements

Knowledge Level


Less than 1 month 1 2 1 2.971 6 0.813

3.20% 2.20% 2.90% 1-3months 3 19 8

9.70% 21.30% 22.90% 3-6months 5 15 4

16.10% 16.90% 11.40% 6 months & Over 22 53 22

71.00% 59.60% 62.90%

3. Frequency of buying

supplements

Knowledge Level


Every month 11 29 12 6.196 8 0.625

35.50% 32.60% 34.30% Every 3 month 12 30 7

38.70% 33.70% 20.00% Every 6 month 3 17 6

9.70% 19.10% 17.10% Once a year 3 8 6

9.70% 9.00% 17.10% Others 2 5 4

6.50% 5.60% 11.40%

4. Average

spending/month

Knowledge Level


Less than 500 Baht/month 4 12 5 6.709 8 0.568

12.90% 13.50% 14.30% 501-1,000 baht 13 31 16

41.90% 34.80% 45.70% 1,001-1,500 baht 5 28 6

16.10% 31.50% 17.10% 1,501-2,000 baht 6 9 3

19.40% 10.10% 8.60%


46

2,000 baht &above 3 9 5

9.70% 10.10% 14.30%

5. Repurchasing Knowledge Level


Yes 24 61 20 3.154 2 0.207

77.40% 68.50% 57.10% Maybe 7 28 15

22.60% 31.50% 42.90%

APPENDIX E-f

CONTINGENCY COEFFICIENT AND GAMMA VALUES FOR

KNOWLEDGE GROUPS AND USAGE PATTERN

Knowledge level and usage

pattern

Contingency

coefficient Gamma

1. Frequency of taking supplements 0.209 0.161

2. Length of taking supplements 0.137 -0.109

3. Frequency of buying

supplements 0.196 0.118

4. Average spending/month 0.204 -0.044

5. Repurchasing 0.141 0.267

APPENDIX F-a MEANS OF ATTITUDE TOWARDS DIETARY SUPPLEMENTS

Attitude Mean Standard

Deviation

1. Dietary supplements help improving overall health 3.955 0.742

2. Dietary supplement is important to you 3.639 0.780

3. Dietary supplements help preventing future

diseases 3.587 0.999

4. I take dietary supplement as I could not get

sufficient nutrition from food 3.826 0.862

5. I consult with doctor before purchasing 3.916 1.075

6. Dietary supplement is safe 3.490 0.907

7. I believe in labels of dietary supplements 3.497 0.900

8. I believe in advertising of dietary supplements 3.110 0.991


47

APPENDIX F-b

CROSS TABULATION BETWEEN ATTITUDE AND USAGE

PATTERN

1. Frequency of

taking

supplements

Attitude and satisfaction level

Low Medium High Very

High X2 df p-value

4-7days/week 3 31 68 12 8.22 9.00 0.510

75.00% 60.80% 81.00% 75.00% 1-3days/week 1 11 8 3

25.00% 21.60% 9.50% 18.80% Less than 1

day/week 0 1 1 0

0.00% 2.00% 1.20% 0.00% When possible 0 8 7 1

0.00% 15.70% 8.30% 6.30%

2. Length of

taking

supplements



High X2 df p-value

Less than 1 month 0 3 1 0 7.45 9.00 0.590

0.00% 5.90% 1.20% 0.00% 1-3 months 2 11 15 2

50.00% 21.60% 17.90% 12.50% 3-6months 0 8 14 2

0.00% 15.70% 16.70% 12.50% 6 months & Over 2 29 54 12

50.00% 56.90% 64.30% 75.00%

9, Dietary supplements in the market have reasonable

price 3.058 0.975

10. Dietary supplement is worth the money 3.465 0.832

11. I will continue to buy supplements even though I

do not see the effectiveness but I believe it is good 2.987 1.217

12. Dietary supplement is effective 3.903 0.691

13. I am satisfied with dietary supplements I am

currently taking 3.929 0.685

14. I will recommend dietary supplements to others 3.794 0.873

Overall 3.582 0.555


48

3. Frequency of

buying

supplements



High X2 df p-value

Every month 0 17 33 2 33.584 12 .001*

0.00% 33.30% 39.30% 12.50% Every 3 month 0 16 27 6

0.00% 31.40% 32.10% 37.50% Every 6 month 4 9 8 5

100.00% 17.60% 9.50% 31.30% Once a year 0 7 10 0

0.00% 13.70% 11.90% 0.00% Others 0 2 6 3

0.00% 3.90% 7.10% 18.80%

4. Average

spending/month



High X2 df p-value

Less than 500

Baht/month 3 9 8 1 23.31 12.00 .025*

75.00% 17.60% 9.50% 6.30% 501-1,000 baht 1 19 36 4

25.00% 37.30% 42.90% 25.00% 1,001-1,500 baht 0 14 18 7

0.00% 27.50% 21.40% 43.80% 1,501-2,000 baht 0 6 9 3

0.00% 11.80% 10.70% 18.80% 2,000 baht

&above 0 3 13 1

0.00% 5.90% 15.50% 6.30%

5. Repurchasing



High X2 df p-value

Yes 1 33 55 16 11.38 3.00 0.010*

25.00% 64.70% 65.50% 100.00% Maybe 3 18 29 0

75.00% 35.30% 34.50% 0.00%


49

APPENDIX F-c

ONE-WAY ANOVA RESULT FOR SPENDING LEVEL AND

ATTITUDE

ANOVA

Sum of

Squares

df Mean

Square

F Sig.

1. Dietary supplements

help improving overall

health

Between Groups 1.635 2 0.817 1.496 0.227

Within Groups 83.049 152 0.546

Total 84.684 154

2. Dietary supplement

is important to you

Between Groups 0.300 2 0.150 0.244 0.784


Total 93.768 154


help preventing future

diseases

Between Groups 12.291 2 6.145 6.611 0.002*

Within Groups 141.284 152 0.929

Total 153.574 154

4. I take supplement as

I do not get sufficient

nutrition from food

Between Groups 10.803 2 5.402 7.933 0.001*

Within Groups 103.493 152 0.681

Total 114.297 154

5. Consult with doctor

before purchasing

Between Groups 9.171 2 4.585 4.131 0.018*

Within Groups 168.739 152 1.110

Total 177.910 154

6. Dietary supplement

is safe

Between Groups 0.715 2 0.358 0.431 0.650

Within Groups 126.020 152 0.829

Total 126.735 154

7. I believe in labels of

dietary supplements

Between Groups 0.015 2 0.008 0.009 0.991

Within Groups 124.733 152 0.821

Total 124.748 154

8. I believe in

advertising of dietary

supplements

Between Groups 0.554 2 0.277 0.280 0.756

Within Groups 150.581 152 0.991

Total 151.135 154


in the market have

reasonable price

Between Groups 1.245 2 0.623 0.652 0.523

Within Groups 145.232 152 0.955

Total 146.477 154

10. Worth the money Between Groups 1.678 2 0.839 1.216 0.299

Within Groups 104.877 152 0.690

Total 106.555 154

11. Will repurchase as

I believed it is good

Between Groups 0.078 2 0.039 0.026 0.974

Within Groups 227.896 152 1.499

Total 227.974 154

12. Supplement is

effective

Between Groups 0.128 2 0.064 0.133 0.876


Total 73.548 154


50

13. Satisfied with

supplements

Between Groups 0.744 2 0.372 0.791 0.455


Total 72.219 154

14. Will recommend

supplements to others

Between Groups 1.790 2 0.895 1.177 0.311

Within Groups 115.604 152 0.761

Total 117.394 154

APPENDIX F-d CORRELATION MATRIX OF THE ATTITUDE

1. Improving overall health2. Important to you3. Help preventing future diseases4. I take supplement as I do not get sufficient nutrition from food5. Consult with doctor before purchasing6. Dietary supplement is safe7. I believe in labels 8. I believe in advertising 9, Dietary supplements in the market have reasonable price10. Worth the money11. Will repurchase as I believed it is good12. Effective 13. Satisfied with supplements14. Recommend to others

1. Improving overall health 1.000 .645 .439 .343 .289 .313 .306 .334 .417 .466 .410 .435 .403 .447

2. Important to you .645 1.000 .324 .350 .273 .426 .461 .438 .429 .480 .358 .453 .426 .509

3. Help preventing future diseases .439 .324 1.000 .316 .324 .139 .172 .079 .145 .193 .359 .299 .156 .237

4. I take supplement as I do not get sufficient nutrition from food .343 .350 .316 1.000 .412 .243 .271 .167 .198 .159 .171 .146 .210 .185

5. Consult with doctor before purchasing .289 .273 .324 .412 1.000 .222 .198 .094 .203 .116 .178 .094 .089 .141

6. Dietary supplement is safe .313 .426 .139 .243 .222 1.000 .622 .518 .401 .359 .300 .345 .328 .301

7. I believe in labels .306 .461 .172 .271 .198 .622 1.000 .609 .455 .401 .320 .381 .310 .313

8. I believe in advertising .334 .438 .079 .167 .094 .518 .609 1.000 .558 .442 .378 .338 .423 .364

9, Dietary supplements in the market have reasonable price .417 .429 .145 .198 .203 .401 .455 .558 1.000 .615 .340 .384 .376 .334

10. Worth the money .466 .480 .193 .159 .116 .359 .401 .442 .615 1.000 .378 .474 .571 .482

11. Will repurchase as I believed it is good .410 .358 .359 .171 .178 .300 .320 .378 .340 .378 1.000 .446 .318 .395

12. Effective .435 .453 .299 .146 .094 .345 .381 .338 .384 .474 .446 1.000 .671 .602

13. Satisfied with supplements .403 .426 .156 .210 .089 .328 .310 .423 .376 .571 .318 .671 1.000 .638

14. Recommend to others .447 .509 .237 .185 .141 .301 .313 .364 .334 .482 .395 .602 .638 1.000

Correlation Matrixa

Correlation

a. Determinant = .002



2. Important to you .645 1.000 .324 .350 .273 .426 .461 .438 .429 .480 .358 .453 .426 .509








10. Worth the money .466 .480 .193 .159 .116 .359 .401 .442 .615 1.000 .378 .474 .571 .482


12. Effective .435 .453 .299 .146 .094 .345 .381 .338 .384 .474 .446 1.000 .671 .602



Correlation Matrixa

Correlation




2. Important to you .645 1.000 .324 .350 .273 .426 .461 .438 .429 .480 .358 .453 .426 .509








10. Worth the money .466 .480 .193 .159 .116 .359 .401 .442 .615 1.000 .378 .474 .571 .482


12. Effective .435 .453 .299 .146 .094 .345 .381 .338 .384 .474 .446 1.000 .671 .602



Correlation Matrixa

Correlation



51

APPENDIX F-e

COMMUNALITIES OF THE ATTITUDE

APPENDIX F-f TOTAL VARIANCE EXPLAINED OF THE ATTITUDE

Total Variance Explained

Factor

Initial Eigenvalues Extraction Sums of Squared

Loadings

Rotation Sums of Squared

Loadingsa

Total % of

Variance Cumulative

% Total % of

Variance Cumulative

% Total

1 5.681 40.580 40.580 5.262 37.588 37.588 3.867

2 1.554 11.097 51.677 .999 7.136 44.725 2.565

3 1.318 9.415 61.092 .926 6.613 51.338 3.140

4 .833 5.947 67.039 .409 2.921 54.259 3.692

5 .778 5.555 72.594

6 .660 4.717 77.310

7 .576 4.116 81.426

8 .543 3.876 85.302

9 .444 3.169 88.472

10 .389 2.780 91.252

11 .380 2.715 93.967

12 .344 2.457 96.423

13 .296 2.117 98.540

14 .204 1.460 100.000

Extraction Method: Principal Axis Factoring.

a. When factors are correlated, sums of squared loadings cannot be added to obtain a total variance.

Initial Extraction

1. Improving overall health .533 .601

2. Important to you .554 .551

3. Help preventing future diseases .322 .401

4. I take supplement as I do not get sufficient nutrition from food .287 .342

5. Consult with doctor before purchasing .254 .339

6. Dietary supplement is safe .447 .539

7. I believe in labels .546 .714

8. I believe in advertising .548 .601

9, Dietary supplements in the market have reasonable price .513 .649

10. Worth the money .552 .633

11. Will repurchase as I believed it is good .348 .314

12. Effective .587 .667

13. Satisfied with supplements .622 .654

14. Recommend to others .520 .593

Communalities

Extraction Method: Principal Axis Factoring.


52

BIOGRAPHY

Name Sunhaporn Wongsawasdi

Date of Birth October 24, 1988

Education Attainment Bachelor of commerce

University of Victoria, Victoria, Canada

Work Position Director Assistant

Bangkok Health Integrative Wellness

Documents

Consumer knowledge, attitude, and purchasing behavior on